Never borrow significant amounts of money or buy cars off friends.
Surefire way to end the friendship.

Never buy an "x" off a professional "x"er. Mechanics don't maintain their cars, IT guys don't maintain their computers. Nobody likes coming home from work and having to do more fucking work, only for free this time.
(Kroney, Thu 3 May 2012, 12:14,
Reply)

Also, never 'go black', as once you have, apparently, you become unable to 'go back'.